Industrial and medical conglomerate Danaher Corp (DHR.N) said it will buy diagnostics company IRIS International Inc (IRIS.O) for $355 million. Danaher will pay $19.50 in cash for each IRIS share, a 45.3 percent premium to the stock's Friday's close. Danaher said the deal value comes to about $338 million, after including IRIS' debt and net cash acquired. IRIS, which makes tests to analyze urine and blood, will become part of Danaher's Beckman Coulter Diagnostics. The offer for all IRIS' outstanding shares will start within the next 7 days, and will remain open for the minimum of 20 business days, IRIS said in a statement.